@grs21 said:

I'm trying to get information about the actor playing in a selected movie. Can I do that?

Sure, to get the credits of a movie, call the /credits method. To get the details about a specific person, call the /person/{id} method.

Or I could not find the required url part for it, is there a player url?

I'm not sure I understand, a player URL for what exactly?

I actually want to list the actors who played in the selected movie. I could not find this information in the GET DETAIL section or other sections. Where can I get information? Thanks your answer.

@grs21 said:

I actually want to list the actors who played in the selected movie.
I could not find this information in the GET DETAIL section or other sections.
Where can I get information? Thanks your answer.

There are 2 ways to obtain a cast list for a specific film.
For example the film with ID 550.
https://www.themoviedb.org/movie/550-fight-club

1 - Making a Get Credits API Request, specific to cast and crew
See here https://developers.themoviedb.org/3/movies/get-movie-credits
Example https://api.themoviedb.org/3/movie/550/credits?api_key=THE_KEY&language=en-US

2 - Or by doing a basic Get Details API Request with the &append_to_response= feature
See here https://developers.themoviedb.org/3/movies/get-movie-details
See here https://developers.themoviedb.org/3/getting-started/append-to-response
Example https://api.themoviedb.org/3/movie/550?api_key=THE_KEY&language=en-US&append_to_response=credits